Work on severe endemic trachoma in North Africa (Tunisia and Egypt) has led to a systematic analysis of the epidemiology of the disease so that the effect of intervention can be better planned. With this background it has been possible to make a total approach to the strategy of preventing blindness from trachoma in endemically infected populations. Techniques are being developed for assessment of blindness in developing countries in conjunction with the World Health Organization. These techniques will be field tested in the coming year in Southern Tunisia and one governerate (province) in Egypt. Experiments on guinea pig inclusion conjunctivities are being continued to explore the immunity to challenge inoculation that develops in this chlamydial infection that is an animal model of trachoma. In our clinical studies of herpes simplex eye infections, we have developed a systems analysis model of the disease process which explains the effect of various commonly used medications (antivirals, corticosteroids) and gives guidelines for rational management of the disease. Experimental studies on herpetic eye infections in rabbits have led to the discovery that acute eye infection is followed by infection of the autonomic ganglia as well as the sensory ganglia. Further experiments on the role of the autonomic ganglions in recurrent herpetic eye disease will be carried out in rabbits and guinea pigs. A model of recurrent eye disease in guinea pigs will be studied so that methods of prevention can be evaluated.